Metal cap for electric incandescent lamps.



E. STREHLER.

METAL CAP, FOR ELECTRIC INCANDESYCENT LAMPS. APPLICATION FILED MAY 9. 1912.

EMIL STEEHLER, 0F STEIN, SWITZERLAND.

METAL CAP FOR ELECTRIC INCANDESCENT LAMPS.`

Specicaftion of Letters Patent.

rat-enten oct. 19, 1915.

Application led May 9, 1912. Serial No. 696,192.

at Stein, Switzerland, have invented certain new and useful Improvements in Metal Caps for Electric Incandescent Lamps, of which the following is a specification.

.The metal caps for electric incandescent lamps of'known construction comprising a cap which serves as support for theglass bulb of the lamp insulated from the contact cap have the inconvenience that they are very heavy owing to the insulating body. This circumstance not only increases the expenses connected with the transport ofthe lamps but it further increases the percentage of breakage caused by the vibrations resulting from the heavy weight. A further in. convenience connected with the manufacture of suchV lamps is that misfits very often happen owing to the insulating of the rim the interposition of a glass body which has to be pressed in at the heated state.

This invention obviates the hereinbefore mentioned inconveniences by connecting` the contact cap and the cap for the glass bulb by means of an insulating material which is deformable at the cold state.

. In the accompanying drawings two forms of construction of the improved metal cap are shown by way of example.

Figure l represents the contact cap a open at the lower end 4and carrying the usual screw-contact. This cap a has at its open end two parallel fianges b and o between which a ring d is located which is made of insulating material such as insulating paper, india rubber or the like. The inwardly bent edge of the cap e designed to receive the glass bulb of the lamp is inserted in said insulating ring whereby this glass bulb is securely connected with the contact cap but perfectly insulated from the same. The ring cl can further be composed of two or more separate rings for example of two annular disks made of card board and of an indiarubber ring placed against the contact cap and embracing the card board rings.

According to Fig. 2 the lower open endof the contact cap a is telescoped into an upwardly proJecting rim of the socket e and rigidly connected with the same by means of a collar f, an insulating ring d belng inserted betweenthe contact cap and the socket. This insulating ring is of similar construction and material as the ring described with reference to' Fig. 1 that is to say it is made of an insulating material which is iiexible and deformable in the cold state such as for example card-board, indiarubber or asbestos.

l. Metal cap for electric incandescent lamps, comprising in combination, a contact cap open at its lower end and provided at said end with acircularrim, a cap for the reception of the glass bulb provided at its upper-end with a circular rim, the rim of one of said caps surrounding the adjacent rim of the second cap, and a ring of -insulating material deformable in a cold state arranged between said two rims and held in place thereby.

2. Metal cap for electric incandescent lamps comprising in combination, a contact capopen at its lower end and having at said end a rim consisting of two parallel anges, a ring of insulating material deformable in a cold state inserted between said two flanges, and a cap for the reception of the glass bulb provided with an inwardly bent upper rim sprung into said insulating ring to securely connect the cap for' the glass bulb to the contact cap.

3. In an electric incandescent lamp, a cap or collar member for holding the smaller end of an incandescent bulb, one end of said collar having a continuous flange portion of less diameter .than its body, a screw-threaded cap to be secured to said collar member, said screw-threaded cap having formed at one end thereof a continuous peripheral engaging portion in forced intertting engagement with said fiange, and an insula-V tion deformable in the cold-and clamped between said interlocking portions and heldin place by the resiliency thereof.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

EMIL STREHLER.

iwitness'es: I

CARL LUBLER, Hm'NRcHRrNDERxNEoHT. 

